When Jillian Michaels quit “The Biggest Loser” for the third time last June, it opened the door for a new, well-toned trainer on the weight-loss competition show.

Filling Michaels’ sneakers for Season 16 are two new faces — Jessie Pavelka and Jennifer Widerstrom — who join returning trainers Bob Harper and Dolvett Quince for the Sept. 11 season premiere (8 p.m./Ch. 4).

Though the rookies admire Michaels, known for her drill-sergeant approach, “We are totally different. We bring our own thing to the show and in no way did we think we have to replicate what she did,” says Pavelka.

Both bring a TV background to their “Biggest Loser” debuts. Widerstorm starred in the 2008 NBC reality show “American Gladiators” before working as a trainer in LA for the last six years. Pavelka — a distant relative of one-time “Bachelor”/“Bachelorette” Jake Pavelka, though they’ve never met — is a former professional bodybuilder who found his calling working with gastric bypass patients. He’s appeared on weight-loss shows on Lifetime, OWN and in the UK.

In the show’s latest iteration, “The Biggest Loser: Glory Days,” the trainers will be helping 20 contestants who are all former athletes — including ex-NFL players Scott Mitchell and Damien Woody and Olympic gold medalist tennis player Zina Garrison.

Their familiarity with fitness allowed the trainers to skip the basics — like the correct position for a squat, how to hold a dumbbell, where the quad muscle is located — and to push the contestants harder, knowing they could take it.

“It’s really expedited the process of fitness and wellness,” Widerstrom says. “As athletes, I just need to remind them of what they’re capable of and put them in scenarios where those feelings become familiar.

“If you can find that edge in those people, man, they will work for you. [The show has] been reinvented in a really special way.”

Another new element this season is the addition of the “Comeback Canyon,” where eliminated contestants will be given a second chance to be trained by Harper and compete at a separate secret weigh-in for the opportunity to return to the competition for a shot at the $250,000 prize.

“We look at the ranch as a microcosm for life, we all deserve a second chance, we all make mistakes,” Pavelka says. “Sometimes on the ranch the best people have a bad week and they end up going home. It throws a whole new dynamic and definitely makes it more entertaining for the person at home.”